Instrument for cooling smoke



April 9, 1963 M. M. SMITH INSTRUMENT FOR COOLING SMOKE Filed April l,1960 'fill/All.

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ww RN Www Wg. dm'Z' United States Patent O 3,084,698 INSTRUMENT FORCOOLING SMOKE Marvin M. Smith, 1010 E. Parkway Drive, Muncie, Ind. FiledApr. 1, 1960, Ser. No. 19,276 11 Claims. (Cl. 131--194) This inventionrelates to an improved means for cooling smoke in a smoking instrumentand to remove undesirable tars and other volatile materials from thesmoke. More particularly, this invention relates to an improved pipe orthe like which provides a new instrument utilizing the unique propertiesof thermoelectric semi-conductors to provide a Peltier refrigeratingcell activated by a Seebeck generator activated by the heat from theburning tobacco, to cool the smoke passing through the stem to themouthpiece.

Although the instant invention is applicable to a wider range of subjectmatters than to tobacco smoking instruments, the invention arose as asolution to the particular problems there posed. Recently much researchand investigation has been undertaken in regard to an allegedcorrelation between heavy smoking and lung cancer. While the studieshave revealed a high correlation between heavy smoking and lung cancerno causative relationship has yet been proven although the correlationis so high as to imply that one does exist. Among the factors believedto be more probably responsible for producing the carcinogenic eiect arethe volatile tars and other substances which are produced by the burningtobacco and transmitted in gaseous form to the lungs of the smoker wherethe volatile materials are condensed, leaving deposits on the lungs.These substances cumulatively have been shown to produce cancer in thelungs of other animals, notably rats.

In analyzing the transmission of these substances from the burningtobacco to the lungs of the smoker it is to be particularly noted thatfrom the time the smoke leaves the burning tobacco until it enters intothe mouth of the smoker it is not cooled sufficiently to condense theundesirable tars and substances from the smoke stream.

Therefore, it is a primary object of this invention to provide a smokinginstrument which includes means for the condensation of the tars andother Volatile or vaporized substances from the smoke stream prior toentering the mouth of the smoker.

It is a further object of this invention to provide a means forcondensing undesirable tars and moisture from a smoke stream flowingthrough a smoking instrument which means may be practiced within theconventional length limitations of such devices and which may provide atemperature diiferential of signiicant magnitude to effect an improvedeffective condensation and tar removal beyond that which could normallybe expected from conventional filter devices.

However, in order to create the necessary temperature differential, somerefrigerating means is necessitated which can establish a temperature inthe smoking instrument, adjacent the smoke stream, below that of theambient temperature. Such refrigerating devices necessarily call for asource of energy to produce such heat absorption to accomplish suchcooling.

To provide for the cooling effect, the present invention utilizes aPeltier refrigerating cell employing a pair of different thermoelectricsemi-conductor materials which, when activated by electrical energy,produce a cooling effect. Such a Peltier cell can be constructed on aVery miniature scale to fit the demands and limitations of the ordinarypipe or the like or, for that matter, laboratory equipment which maynecessitate condensation of volatile materials from smoke.

However, the problem remains as to what source of 3,084,698 PatentedApr. 9, 1963 ICC energyV could be utilized to activate the Peltierrefrigeration cell. Once again, the limitations imposed by the size ofpipes, cigarette holders and laboratory equipment necessitate that suchenergy supplying means be limited severely in size and yet producesufficient current to activate the Peltier cell to furnish the requiredcooling of the smoke stream. To solve this the instant invention teachesthe use of a Seebeck generator which utilizes the heat from the burningtobacco to create an electrical current to activate the Peltier cell.While this is the preferred embodiment, since it is self energizing,this invention also recognizes that a small mercury cell battery couldbe used within the limitation imposed by the size of cigarette holdersand pipes to furnish the required current to the Peltier cell.

Therefore it is a further object of this invention to provide a smokinginstrument which includes a self energizing cooling unit; and moreparticularly, which employs a Seebeck generator actuated by the burningtobacco to provide current to a Peltier refrigeration cell to cool thesmoke stream, before it reaches the smokers mouth, and to perform thebefore mentioned changes of the physical properties of the volatiles andmoisture carried by the smoke.

Other objects and advantages of the instant invention are to provide aparticularly effective and inexpensive smoke cooling arrangement ofelements within the limitations of space imposed by conventional smokinginstruments; to provide the most eiiective materials for achievingcondensation of tars from the smoke flow; to provide a durable, reliableinstrument having no moving parts which obviates the possibility ofbreakdown and the necessity for repair.

Other objects and advantages of the instant invention will be apparentfrom following description and the specie embodiments of the inventionshown in the accompanying drawings in which:

FIGURE l is a side elevational view of a pipe of conventional formutilizing the instant invention;

FIG. 2 is an enlarged central longitudinal view in section showing theimproved smoke cooling and condensing unit embodied within a pipe havinga radiator section in the pipe stem;

FIG. 3 is a partial cross-sectional view taken substantially on theplane of line 3-3 in FIGURE 2;

FIG. 4 is a cross-sectional view taken substantially on the plane ofline 4-4 in FIGURE 2;

FIG. 5 is a side elevational view, with parts shown in section, of thecondensation and cooling unit per se; and

FIG. 6 is a cross-sectional view, as taken substantially on the plane oflines 3 3 in FIGURE 2, showing a moditied arrangement for the positiveand negative legs of the cooling unit for increasing the operatingcapacity of the assembly.

Although the particular cooling and condensation unit embodying themeans which are the subject of the instant invention is shown as appliedto a pipe it is to be particularly noted that this unit can be appliedto many analogous installations and situations, including use withcertain laboratory types of equipment, without departing from the spiritof this invention.

As seen in FIGURE l, the instant invention is particularly adapted foruse with a conventional pipe including a wooden bowl which receivestobacco which is burned therein to provide smoke which normally flowsthrough an appropriate bore formed within a plastic or hard rubber stem3 when the smoker draws upon the mouthpiece 5 at the end of the stem 3.

As best seen in FIGURE 5 the smoke cooling and condensation means may beformed :as a compact unit which is fitted into the bore 7 from the smokeentering end of the stem 3 and which is appropriately secured therein.

Generally, the smoke cooling and condensation unit is comprised of acentral elongated metallic smoke and condensation tube 9, made of anappropriate metal such as aluminum, through which all the smoke isconfined to travel to the mouthpiece and around the smoke entering endof which is secured a Seebeck generator 11 which receives heat from theburning tobacco and converts it into electricity which activates aPeltier refrigerating cell 13 which surrounds the tube 9 adjacent theoutlet end.

More particularly, the Seebeck generator 11 includes a metallic junctionband 15 to which the ends of the negative leg 17 and the positive leg 19are integrally secured so as to be thermally and electricallyconductive. The junction band 15, as shown, is generally cylindrical andhas a bore 21 extending axially therethrough. This bore is counterbored,for about three fourths the length of the cylinder, to a diametersufiiciently larger than the outside diameter of the condensation tube 9to receive the end portions of tube 9 and an axially extendinginsulating sleeve 20, which surrounds the tube 9, therein. Preferablythe lbore of the tube 9 and the bore 21 of the cylinder 15 are of thesame diameter and the end of the sleeve 20, adjacent the pipe bowl,extends beyond the end of the tube and is internally enlarged to thediameter of the tube bore to provide an unbroken surface for the passagethrough which smoke may -be drawn from the bowl through the tube 9 tothe mouthpiece 5.

The negative leg 17 and the positive leg 19 are substantially identicalin length and are arranged around the periphery of the tube 9 in axiallyparallel relation therewith and with respect to each other and may besecured to the junction 15 by means of appropriate holes drilled in thejunction and by brazing or other conventional means. These legs 17 and19 are further insulated both electrically and thermally from tube 9 bymeans of the insulation sleeve 20 which extends lengthwise of the tubebetween the tube and the legs. The legs 17 and 19 should -beappropriately located on the junction cylinder 15 so that each receivesa substantially equal amount of heat therefrom. In the instant case, dueto the length of the junction cylinder 15 as shown, the heat is diffusedthroughout the junction and the body of the junction serves to transmitsubstantially equal amounts of heat to the ends of the legs V17 and 19.

'Ille negative leg 17 and the positive leg 19 may be made of any twodifferent thermoelectric semi-conductor materials. Materials foundsuitable for this purpose are bismuth telluride for the negative leg 17and lead telluride for the positive leg 19. It is to be emphasized,however, that any two different thermoelectric semi-conductor materialsmay be used.

The Peltier refrigeration cell 13 is actually the converse of theSeebeck generator. The Peltier refrigeration cell includes a junctionbody 27 which is shown as being generally annular in construction to fitwithin the bore 7 of the pipe stem. This junction 27 is of anelectrically conductive metallic material, preferably aluminum, and isprovided with appropriate -bores for receiving negative leg 29 andpositive leg 31 which are bonded therein in any conventional fashion.The negative leg 29 and the positive leg 31 may be identical with thenegative leg 17 and the positive leg 19, respectively, but for practicalpurposes the semi-conductors in the Seebeck unit or cell 11 should be ofa material able to withstand higher temperatures than the material inthe semi-conductors of the Peltier cell 13. Further, these legs 29-3'1are mounted in the same manner as the legs 17-19 and are insulated fromthe tube 9 by means of the insulating tube 20, which extendstherebetween, as shown in FIGURE 2.

The central bore 33 of the annular connector body 27 receives the smoketube 9 which is tightly fitted therein to provide efficientthermo-conductivity therebetween.

As shown, the smoke tube 9 extends outwardly beyond the junction body 27and into the mouthpiece to provide as much cooling and condensationsurface as may be possible for the smoke traveling therethrough. Also,as indicated at 10` in FIGURE 5, the smoke tube 9 may be in two sectionsconnected end to end by a suitable insulating material so that heat fromthe section at the hot end will not have a direct path to the cool end.It is to be noted that the annular body Z7 and the metallic junctionband 15 cooperate to provide a firm support within the pipe stem for thegenerator and cooling unit assembly.

When the negative leg 17 is connected to the positive leg 31 and thenegative leg 29 is connected to the positive leg 19, the Seebeck andPeltier cells are then connected in electrical series providing acomplete circuit for the flow of any current produced by the generatoror Scebeck unit. The amount and voltage of current generated by theSeebeck unit, is, of course, determined by the heat applied to thejunction band or cylinder 15 and by the mass of the negative andpositive legs of semi-conductor material. Where the heat source islimited, as in the devices herein described and shown, the generatingcapacity of the Seebeck unit can be increased by employing additionalnegative and positive legs arranged as shown in FIGURE 6, wherein 29'and 31 indicate the added elements in a Peltier cell, the Seebeck andPeltier cells being of the same general form.

In operation the previously described smoking instrument operates asfollows:

When the tobacco in the bowl 1 is substantially in the position shown inFIGURE 2 the burning of the top layer will provide hot smoke which isdrawn through the remainder of the tobacco in the bowl, through thealuminum tube 9 and the mouthpiece 5, and into the mouth of the smoker.Due to the amount of tobacco initially in the bowl 1, the smoke will besomewhat cooled and filtered yas it moves through this tobacco to demandonly a minimal amount of cooling by the cooling and condensing unit.However, as the tobacco continues to burn downwardly in the bowl lessand less tobacco will be present to filter and cool the smoke and hencethe smoke traveling through tube 9 during this portion of the burningwill be much hotter and will present a relatively great demand forcooling. To appropriately accommodate the different loads which willthus be placed upon the cooling and condensation unit, the metallicjunction 15 is positioned adjacent the bottom interior of the bowl toprovide a maximum exposure to the heat source. Thus the heat which isreceived by the metallic junction 15, Whether by conduction, radiationor convection, is generaly proportional to the temperature of the smokeentering the tube 9 and hence the load of volatiles and tars in thesmoke. In this manner the generating and cooling capacity of theassembly is substantially self-regulating according to demand.

Junction 15, because of its mass, serves to diffuse the heat receivedthroughout its surface so that the negative leg 17 and the positive leg19 are subjected to the same temperature. These different thermoelectricsemi-conductor legs react to heat applied to the connected ends in anunknown manner to produce a current flow through any secondaryconductive device connected across the opposite ends of the legs. In thedevice shown in FIG- URE S, this current flow is conducted to the legsof opposite polarity in the Peltier refrigerating cell 13 to stimulatethis cell at its forward end, to produce a significant cooling effect atits rearward end where the legs 29 and 31 are connected by the junctionelement 27. This cooling of the junction body 27, which also acts as anelectrical connector to complete the circuit through the Peltier andSeebeck cells, makes the Abody 27 act as a refrigerator which, becauseof its thermal contact with a relatively large area of the smoke tube 9,creates a significant temperature differential between the smoke er1-tering end of that tube and the rear end from which the smoke enters theusers mouth so that the smoke is cooled to a greater extent than ispossible with ordinary smoking devices. v

When the smoker initiates any drawing action on the mouthpiece 5 4thetobacco is caused to burn more rapidly in the bowl causing more heat tobe immediately received by junction band `15, both by radiation andconvection, as well as -by conduction through the bowl body, therebyincreasing the electric current flowing to the Peltier cell to reducethe temperature of the junction body 27 and the adjacent area of thesmoke tube 9. As the smoke passes through the cooled rear portion of thesmoke tube, the smoke is not only cooled but also the volatile tars andother -deleterious materials contained in the smoke are condensed out ofthe smoke and thus removed before the smoke enters into the smokersmouth. Indeed, the combination effect is to produce a cooler smokehaving less toxic materials likely to affect the health of the smoker.-It will be understood that some heat is extracted from the smoke streamby the junction band 15. However, because the band is also heated -byradiation and convection, the major and most effective cooling of thesmoke is done in the rearward portion of the tube 9 under the influenceof the Peltier cell junction band 27.

The peculiar characteristics of thermoelectric semiconductors as used inthe Peltier cell results in an absorption of heat at one end of the celland a production of heat at the other end of the cell when the cell istraversed by `an electric current. This is a widely known phenomenareferred to as the Thomson effect. Therefore, cooling from the outsideof the pipe is only necessary to remove the heat of the electricalresistance in the Peltier cell at the end thereof connected to thesource of electrical energy to effect higher eiciency of its coolingfunction. Such cooling from the outside of the pipe may be enhanced byinserting a radiating section 34 in the pipe stem, adjacent the hot endof the Peltier cell, as shown in FIGURE 2. Further, since there areusually time lags or gaps between the smoke loads drawn by the smoker,the constant action of the Peltier reirigerating cell provides a coldsink or temperature drop in the portion of the smoke tube adjacent thejunction band 27 ordinarily suicient to accommodate the heavy loads whenthey do occur.

From the previous description it will be seen that an improved smokinginstrument has been provided which produces a significant cooling `ofthe smoke, sufiicient to condense and remove the tars and other volatilematerials therefrom and which may be practiced within the conventionallength limitations of smoking instruments; which provides a temperaturedifferential, between the entering smoke and the leaving smoke, ofsuicient magnitude to effect an improved cooling of the smoke beyondthat which could be normally expected from conventional filter andthermal radiation devices; which includes a self-energizing coolingunit; and more particularly which employs a Seebeck generator actuatedby the burning tobaccos to provide current for activating a Peltierrefrigeration cell to cool the smoke stream before it reaches thesmokers mouth.

Although but one embodiment of my invention has been herein shown anddescribed it will be understood that details of the structure andarrangement shown may be altered without departing from the spirit ofthe invention as dened by the following claims.

I claim:

1. In `a smoking instrument including means for holding tobacco forburning and a stem for conveying smoke from said holding means to amouthpiece, the improvement comprising a metallic tube in said stem toconvey said smoke therethrough, two pairs of thermo electricsemi-conductor legs, each pair including a negative leg and a positiveleg spaced from each other and from said tube, one of said pairs-terminating adjacent the tobacco holding means and the other pairterminating adjacent the mouthpiece, a first metallic junction means onsaid holding means for conducting heat to the adjacent ends of each ofsaid adjacent legs and connecting said ends electrically, the negativeleg of each of said pairs being electrically connected serially with thepositive leg of the other of said pairs, andan annular metallic junctionelectrically and thermally connecting the ends of the legs adjacent themouthpiece, said tube extending through said annular junction and beingin contact therewith.

2. In a smoking instrument including means for holding tobacco forburning and a stem extending from said holder to convey smoke to amouthpiece, the improvement comprising a metallic -tube in said sternthrough which said smoke is confined to travel, two longitudinallyspaced pairs `of thermo electric semi-conductor legs located in saidstem, each of said pairs including a negative leg and a positive legspaced from each other and from said tube, one of said pairs terminatingadjacent the tobacco holding means and the other pair terminatingadjacent the mouthpiece, a rst metallic junction means abutting saidholding means to conduct heat to the adjacent ends of said one pair oflegs and. providing an electrical connection therebetween, electricaljunction means connecting the adjacent end of each negative leg to theadjacent end of the positive leg of the other pair of legs, a secondmetallic junction electrically and thermally connecting the ends of saidother pair of legs "adjacent the mouthpiece, and said tube extendingthrough said second metallic junction in surface to surface contacttherewith.

3. In a smoking instrument including means for holding tobacco forburning and a stem extending from said tobacco holding means to amouthpiece for conveying smoke thereto, the improvement. comprising ametallic tube in said stem to convey smoke therethrough, a Seebeckgenerator unit mounted within said stem adjacent said holding means, aPeltier refrigerating cell unit mounted Within said stem adjacent saidmouthpiece, said Seebeck generator including negative and positivethermoelectric semi-conductor legs spaced from each other and having ametallic heat conductor means extending into said holding means to beheated by the burning tobacco and thermally and electrically connect theends of said Seebeck legs nearest said holding means, said Peltierrefrigerating cell including negative and positive thermo electricsemi-conductor legs spaced from the other and mounted within 4said stemadjacent sai-d mouthpiece, and having a metallic junction mounted withinsaid stem to thermally yand electrically connect the ends of saidPeltier le-gs nearest to said mouthpiece, and electrical leadsconnecting the free end of the negative thermo electric semiconductorleg of each unit to the adjacent free end of the positive thermoelectric semi conductor leg of t-he opposite unit, said junctionsurrounding said metallic tube in surface to surface contact therewith.

4. In `a smoking instrument including means for hold- -ing tobacco forburning and a stem extending from said holding means to convey smoke toa mouthpiece, the improvement comprising an aluminum tube in :said stemto convey smoke therethrough, a first metallic junction band mounted onsaid holder to be heated by the burning tobacco therein, a rst pair ofelongated legs each of a different semi-conductor material embedded insaid instrument and each having one end thermally connected to saidfirst junction band and the other end extending toward said mouthpiece,a second pair of elongated legs of different semi-conductor materialsconnected in electrical series with said first legs `and embedded insaid stem between said mouthpiece and said rst legs, and a secondmetallic junction band connecting the ends of said second pair of legsnearest said mouthpiece and engaging said tube in surface to surfacecontact.

5. The smoking instrument as described in claim 4, wherein the rstmetallic junction band is located adjacent that portion of the .tobaccoholding means toward which the burning of the tobacco progresses.

6. A smoking instrument comprising a holder for burning tobacco, a stemextending from said holder and terminating in a mouthpiece, a metallicsmoke conducting tube in said stem extending between `said holder andmouthpiece, a Peltier cell in rsaid stern comprising a pair of legs ofmutually different semi-conductor materials, said legs being connectedat one end by a junction band 0f electrically and thermally conductivematerial, means for thermally connecting said junction band and saidsmoke tube, and means for electrically inciting said Peltier unit.

7.' A smoking instrument comprising a holder for burning tobacco, .astem extending from said holder and terminating in a mouthpiece, ametallic smoke tube in said stem extending between said holder andmouthpiece, a Peltier cell in said stem comprising a pair of legs ofdifferent semi-conductor materials, said legs being connected at one endby a junction band of electrically and thermally conductive material,means for thermally connecting said junction band `and said smoke tube,means for electrically inciting said Peltier unit, and means in said-stem adjacent the ends of said legs opposite said junction band forradiating heat from said leg ends to the atmosphere surrounding saidstem.

8. In -a smoking instrument including means for holding tobacco forburning and a stem extending from said holding means to convey smoke toa mouthpiece, the improvement comprising an aluminum tube in said sternto convey `smoke therethrough, a first metallic junction band supportedby said holding means and disposed to be heated by the burning tobaccotherein, a iirst pair of elongated legs each of a differentsemi-conductor material embedded in said instrument and each having oneend thermally connected to said rst junction band and the other endextending toward said mouthpiece, a second pair of elongated legs ofdifferent semi-conductor material-s connected in electrical series withsaid rst legs and embedded in said `stem lbetween sa-id mouthpiece andsaid rst legs, a second metallic junction band connecting the ends ofsaid second pair of legs nearest said mouthpiece and engaging said tubein surface to surface contact, and means -in said stem adjacent theserially connected ends of said rst and second pairs of `legs forradiating heat from said serially connected ends to the atmospheresurrounding said stem,

9. The smoking instrument as described in claim 8, wherein the firstmetallic junction band is located adjacent that portion of the tobaccoholding means toi-Ward which the burning of the tobacco progresses.

10. Means for condensing volatiles from gaseous products of combustioncomprising a conduit for said gaseous products leading away from acombustion means source thereof, a Peltier cell comprising a pair oflegs of mutually different semi-conductor materials each having one endconnected integrally with a junction band of electrically and thermallyconductive material, a condensation Zone in said conduit remote fromsaid combustion means source, means for connecting said junction bandand said conduit adjacent the condensation zone thereofrand in thermallyconductive relation therewith, and means for electrically inciting saidPeltier unit.

11. Means for condensing volatiles from gaseous products of combustioncomprising, a combustion means normally operating to produce gaseouscombustion products at varying volumetric rates, a conduit for saidgaseous products having a connection with said combustion means toreceive and convey said gaseous products, a condensation zone portion insaid conduit remote from said combustion means, electrically incitedmeans in thermally conductive relation with the condensation zoneportion of said conduit for cooling said condensation Zone, the Coolingeffect of said means being proportional to the electrical incitationthereof, and means operatively controlled by said combustion means forvarying the cooling effect of lthe last named means in direct relationwith the rate of production of said gaseous products by said combustionmeans.

References Cited in the le of this patent UNITED STATES PATENTS,11,571,729 Modine Feb. 2, 1926 2,881,594 Hopkins Apr. 14, 19592,886,618 Goldsmid May 12, 1959 OTHER REFERENCES White Article, pages589, 590 and 591 of Electrical Engineering for July 1951.

3. IN A SMOKING INSTRUMENT INCLUDING MEANS FOR HOLDING TOBACCO FORBURNING AND A STEM EXTENDING FROM SAID TOBACCO HOLDING MEANS TO AMOUTHPIECE FOR CONVEYING SMOKE THERETO, THE IMPROVEMENT COMPRISING AMETALLIC TUBE IN SAID STEM TO CONVEY SMOKE THERETHROUGH, A SEEBECKGENERATOR UNIT MOUNTED WITHIN SAID STEM ADJACENT SAID HOLDING MEANS, APELTIER REFRIGERATING CELL UNIT MOUNTED WITHIN SAID STEM ADJACENT SAIDMOUTHPIECE, SAID SEEBECK GENERATOR INCLUDING NEGATIVE AND POSITIVETHERMOELECTRIC SEMI-CONDUCTOR LEGS SPACED FROM EACH OTHER AND HAVING AMETALLIC HEAT CONDUCTOR MEANS EXTENDING INTO SAID HOLDING MEANS TO BEHEATED BY THE BURNING TOBACCO AND THERMALLY AND ELECTRICALLY CONNECT THEENDS OF SAID SEEBECK LEGS NEAREST SAID HOLDING MEANS, SAID PELTIERREFRIGERATING CELL INCLUDING NEGATIVE AND POSITIVE THERMO ELECTRICSEMI-CONDUCTOR LEGS SPACED FROM THE OTHER AND MOUNTED WITHIN SAID STEMADJACENT SAID MOUTHPIECE, AND HAVING A METALLIC JUNCTION MOUNTED WITHINSAID STEM TO THERMALLY AND ELECTRICALLY CONNECT THE ENDS OF SAID PELTIERLEGS NEAREST TO SAID MOUTHPIECE, AND ELECTRICAL LEADS CONNECTING THEFREE END OF THE NEGATIVE THERMO ELECTRIC SEMICONDUCTOR LEG OF EACH UNITTO THE ADJACENT FREE END OF THE POSITIVE THERMO ELECTRIC SEMI CONDUCTORLEG OF THE OPPOSITE UNIT, SAID JUNCTION SURROUNDING SAID METALLIC TUBEIN SURFACE TO SURFACE CONTACT THEREWITH.